Release Notes
The following excerpt is from the README file included in the project.
Pi4J :: Java I/O Library for Raspberry Pi
==========================================================================
[](https://travis-ci.org/Pi4J/pi4j?branch=master) [](https://maven-badges.herokuapp.com/maven-central/com.pi4j/pi4j-core) 
## PROJECT INFORMATION
Project website: https://www.pi4j.com/ <br />
Project discussion group: https://groups.google.com/forum/#!forum/pi4j <br />
Project issues list: https://github.com/Pi4J/pi4j-v1/issues <br />
<br />
Release builds are available from
* [Maven Central] http://search.maven.org/#search%7Cga%7C1%7Ccom.pi4j
* [Downloads] https://pi4j.com/download.html
Snapshot builds are available from
* [Sonatype OSS] https://oss.sonatype.org/index.html#nexus-search;quick~pi4j
* [Downloads] https://pi4j.com/download.html
Copyright (C) 2012-2021 Pi4J
## LICENSE
Licensed under the GNU LGPLv3 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.gnu.org/licenses/lgpl.txt
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
## KNOWN ISSUES
2021-01-12 :: 1.3
* Pi4J v1.3 must be compiled using JDK 1.8. This codebase is not compatible with JDK9 and newer. Pi4J v1.4
and later will support newer JDKs.
* The original WiringPi library has been **DEPRECATED**. _(See: http://wiringpi.com/wiringpi-deprecated/)_
* To support RaspberryPi 4B and newer systems you must install the latest *unofficial* WiringPi version which is
maintained here: https://github.com/WiringPi/WiringPi. _(As of 2021-01-12, this is version 2.60.)_
* Please note that the Pi4J v1.x codebase is no longer being actively developed. Pi4J v1.x will only be maintained
and updated for major bug fixes. This codebase has been largely stable for several years and is compatible across
a wide variety of Raspberry Pi SoCs and you are welcome to continue using it. However, for new projects, it
is highly recommended to migrate to the Pi4J Version 2.x codebase. See https://pi4j.com for more information.
2018-04-23 :: 1.2
* As of 2018-04-23, We have removed support for the Pi4J native library statically compiled against WiringPi.
for the Raspberry Pi platform. You must now have WiringPi installed on your target Raspberry Pi system
separately from Pi4J. WiringPi is now included be default in the latest Raspbian builds. We made this change
in part because the WiringPi project now requests no static linking and because it would cause Pi4J to fail
on newer platforms when we were not able to get a new build released in a reasonable and timely manner. This
change should be of a minimal negative impact now that WiringPi is included with the OS and users will benefit
from being able to take advantage of newer WiringPi builds without depending on a new Pi4J build. **Note**: for
RaspberryPi 4B/400 and newer systems, you must install the latest *unofficial* WiringPi version which is
maintained here: https://github.com/WiringPi/WiringPi. _(As of 2021-01-12, this is version 2.60.)_
2016-07-26 :: 1.1
* On the Raspberry Pi Model 3B the hardware-based serial/UART device `/dev/ttyAMA0` has been re-purposed to
communicate with the built-in Bluetooth modem and is no longer mapped to the serial RX/TX pins on the GPIO
header. Instead, a new serial port "/dev/ttyS0" has been provided which is implemented with a software-based UART
(miniUART). This software-based UART ("/dev/ttyS0") does not support PARITY and some have experienced some
stability issues using this port at higher speeds. If you don't need the Bluetooth modem functionality, you can
disable the BT modem and configure the RPi to use a device-tree overlay to re-map the hardware-based serial UART
("/dev/ttyAMA0") back to the GPIO header pins for TX/RX. See the instructions on this page for details on how to
configure the device-tree overlay and disable the bluetooth modem/service:
https://openenergymonitor.org/emon/node/12311
* The Odroid C1/C1+/C2 only permits up to four GPIO pins to be configured with edge detection for both "rising"
and "falling" edges (a.k.a., "both"). Thus, you can only use a maximum of four GPIO input pins with listener
events. You can, however, implement a polling strategy to read a pin state if you need more than 4 input pins.
(see: https://github.com/Pi4J/pi4j-v1/issues/229 & http://odroid.com/dokuwiki/doku.php?id=en:c1_hardware_irq)
* PWM is not supported in the Hardkernel Odroid WiringPi port. Thus PWM is not currently supported by Pi4J for
the Odroid boards (C1/C1+/C2). There is no PWM function on the 30pin GPIO header on the XU3/XU4.
(see: https://github.com/Pi4J/pi4j-v1/issues/229)
* Support for OrangePi and Synovoip BPI platforms is considered experimental and has had limited testing. Not
all Pi4J features may be supported and/or working properly.
## RELEASES
2021-01-28 :: 1.3
* Must be compiled using JDK 1.8
* Install WiringPi v2.60 or later to support RaspberryPi 4B and newer systems.\
(https://pi4j.com/1.3/dependency.html)
* Added support for RaspberryPi 4B
* Added support for RaspberryPi 400
* Added support for RaspberryPi Compute Module 4
* Bug Fixes: https://github.com/Pi4J/pi4j-v1/milestone/10?closed=1
2019-02-27 :: 1.2
* Removed support for statically compiled wiringPi library (for Raspberry Pi).
* Added support for Raspberry Pi 3B+
* Added support for Raspberry Pi Zero W
* Added support for Raspberry Pi Compute Module 3
* Updated to Java 8 (enhancement #203)
* Updated build dependencies/plugins to latest versions.
* Removed unsupported sub-projects (pi4j-temp, pi4j-service).
* Added SPI mode support for Odroid, BananaPi, BananaPro, and OrangePi platforms.
* Added experimental support for OrangePi platform.
* Added experimental support for Synovoip BPI (BananaPi) platform.
* Added experimental support for NanoPi platform.
* Fixed #438: ArrayIndex Out of Bounds when pin address address is >= 100
* Fixed #278: wiringPiSetup*: You must only call this once per program run.
* Fixed #294; added java runtime and compiler check to pi4j helper script
* Fixed #291; W1Device name contains "\n"
* Fixed #275; LCDExample.java doesn't work in release
* Fixed #276; RaspiBcmPin pins not firing pin state change events
* Fixed #198; Problems with data from HMC5883L class
* Fixed #351; Pi4J packages excluded in OSGI manifest ImportPackage declaration
* Fixed #360; Serial.setBreak(TRUE|FALSE) is printing debug lines to stdout
* Fixed #355; ButtonBase Executor Service should be closed on GpioController.shutdown()
* Fixed #356; SystemInfoProvider CPU temperature was divided by 1000 on OrangePi
* Fixed #272; SerialDataEvent should not fire when event.length() == 0
* Fixed #361; SerialFactory isShutdown() state not getting updated on new instance
2016-07-26 :: 1.1
* Added support for Odroid XU4 (see known issues here: https://github.com/Pi4J/pi4j-v1/issues/229)
* Added support for Odroid C1/C1+ (see known issues here: https://github.com/Pi4J/pi4j-v1/issues/229)
* Added support for Raspberry Pi 3 (Model B).
* Added support for Raspberry Pi Zero.
* Added support for BananaPi platform
* Added support for BananaPro platform
* Added non-privileged GPIO example code.
* Added support for enabling non-privileged GPIO access via the Pi4J APIs
* Added support for '/dev/gpiomem' to eliminate 'root' permissions requirement for basic GPIO.
* Added PWM examples
* Added I2C examples
* Added support for native Watchdog.
* Added W1 (1 wire) support.
* Added MCP3204 ADC implementation and example code.
* Added MCP3208 ADC implementation and example code.
* Added MCP3004 ADC implementation and example code.
* Added optimizations for GPIO state change latency
* Added Gpio.pinModeAlt() method to the WiringPi wrappers to set pins to any ALT mode.
* Added cross-compiler support in Maven build
* Added cross-compiler shell script
* Added ADC change background monitoring thread and event notifications.
* Added new Serial JNI implementation to support more advanced serial configuration/operations
* Updated Serial interface to extend from AutoCloseable.
* Updated MCP3008 ADC implementation and example code.
* Updated MCP4725 DAC implementation and example code.
* Fixed #135; Serial communication using 7 Data Bits not working.
* Fixed #180; WiringPiISR() callback causing native crash (NPE)
* Fixed SPI issue where internal buffer was limited to 2048 bytes. Dynamically allocated now.
* Fixed the Pi4J Serial interface to use the new Serial JNI implementation
* Fixed wiringPi serial JNI methods to better support raw data operations
* Cleanup for WiringPi native build
* Cleanup for Pi4J native build
* Now requires Java 7 runtime.
2015-08-30 :: 1.0.1
* Minor updates.
* Update ListenGpioExample.java; simplified infinite loop statement.
* Update BlinkGpioExample.java; simplified infinite loop statement.
* Fixes clear methods of LCDBase.java.
* Update MCP3008Pin.java; incorrect pin number assignments.
* Fix pins.contains() calls that received the vararg array "pin" instead of a "p" instance variable.
2015-04-18 :: 1.0
* Released under GNU LGPLv3 license.
* Added support for RaspberryPi v2 Model B
* Added support for RaspberryPi Model A+
* Added support for RaspberryPi Model B+
* Added support for RaspberryPi Compute Module
* Added support for debounce logic on digital input pin events
* Added support for Button component interface
* Added support for Pibrella device
* Added support for SPI modes
* Added support for building pi4j-native project directly on the Pi (using maven)
* Added easy install/uninstall scripts (get.pi4j.com)
* Added APT package and repository support (repository.pi4j.com)
* Simplified native library loader to find embedded hard-float native lib
* Fixed JDK8 build errors.
* Removed support (and complicated builds) for soft-float ABI
* Updated documentation in preparation for 1.0 release
* Cleaned up build
* Enhancements Added: https://github.com/Pi4J/pi4j-v1/issues?q=label%3Aenhancement+is%3Aclosed+milestone%3A%22RELEASE+1.0%22+
* Bugs/Defects Fixed: https://github.com/Pi4J/pi4j-v1/issues?q=label%3Abug+is%3Aclosed+milestone%3A%22RELEASE+1.0%22+
2013-03-17 :: 0.0.5
* Added support for PCF8574 GpioProvider
* Added sample code for using PCF8574 GpioProvider
* Fixed issue where hard-float ABI was not detected properly when using Oracle JDK 8 early access edition.
https://github.com/Pi4J/pi4j-v1/issues/26
* Added support for Motor and Stepper motor component interfaces.
* Added GPIO based stepper motor implementation and sample program.
* Added support for Motion sensor component interface.
* Added GPIO based motion sensor implementation.
* Added LCD component interface
* Added GPIO based 4/8 bit LCD display component implementation and sample program.
* Added GPIO based 4/8 bit LCD WiringPi example program
* Added support for a GpioController.shutdown() method to cleanup terminate all Pi4J threads and executors.
https://github.com/Pi4J/pi4j-v1/issues/9
* Added support for a user-definable ExecutorServiceFactory to allow user program to provide the implementation
for executor service instances and managed thread pools.
https://github.com/Pi4J/pi4j-v1/issues/10
* Fixed 'java.util.concurrent.RejectedExecutionException' issue where there were not
enough default thread in the pool for concurrent tasks.
https://github.com/Pi4J/pi4j-v1/issues/31
* Fixed issue where SerialDataMonitorThread was not shutting down on program exit.
https://github.com/Pi4J/pi4j-v1/issues/33
* Fixed issue where hard-float ABI was not detected properly when using Oracle JDK 8 early access edition.
https://github.com/Pi4J/pi4j-v1/issues/26
* Added support for exceptions on serial port access methods.
https://github.com/Pi4J/pi4j-v1/issues/8
* Fixed issue where process streams were not being closed properly
https://github.com/Pi4J/pi4j-v1/issues/35
* Fixed issue where serial.write(byte[]) was throwing java.lang.StringIndexOutOfBoundsException
https://github.com/Pi4J/pi4j-v1/issues/37
* Added additional system information API methods to access memory, frequency, CPU temperature, voltage, and board model data.
https://github.com/Pi4J/pi4j-v1/issues/30
* Fixed MCP23008 and MCP23017 getState() return values
* Added support for MCP23S17 GpioProvider
* Added support for Pi-Face GpioProvider
* Added support for Pi-Face Device Interface
* Added MCP23S17GpioExample sample code
* Added PiFaceExample sample code
* Added WiringPiSPIExample sample code
* Added LED component interface and GpioLEDCompoment impl
* Added GpioSwitchCompoment impl
2012-12-16 :: 0.0.4
* Added support for building a Pi4J .deb installer package for Debian/Raspian Linux distribution. (BETA)
* Modified NetworkInfo static methods to permit empty array return values when a network property cannot be obtained.
https://github.com/Pi4J/pi4j-v1/issues/3
* Fixed issue in newer Raspberry Pi 512mb firmware where Pi4J was not compiled against latest wiringPi library and thus not detecting the hardware properly.
https://github.com/Pi4J/pi4j-v1/issues/3
* Fixed defect where Pi4J library prevented consuming program from exiting properly.
https://github.com/Pi4J/pi4j-v1/issues/4
https://github.com/Pi4J/pi4j-v1/issues/6
* Added support for MCP23008 GPIO Provider using I2C bus.
* Added support for MCP23017 GPIO Provider using I2C bus.
* Modified build script to support concurrent soft-float and hard-float native library builds
* Modified build script to include pulling wiringPi sources and compiling when building native library
* Added power controller device interface, base impl, and reference impl
* Added GpioController.provisionXXXPin methods that allow name to be optional
* Relocated project downloads location to google code site; github deprecated downloads.
* Added Google Groups discussion forum to project docs.
* Added getTag() and setTag() to GpioPin interface and impl.
* Added TemperatureConversion utility.
* Added optional blocking argument to GpioPin pulse method to support blocking pulse invocations
2012-10-22 :: 0.0.3-SNAPSHOT
* Refactored Gpio interfaces to permit extensible GpioProviders for add-on devices.
* Refactored Gpio interfaces to separate digital, analog, and PWM types of input and output pins.
* Added support for analog GPIO pins (interfaces, methods and events).
* Added Olimex AVR-IO-M16 GpioProvider to serve as an example of extending a new GpioProvider for GPIO expansion.
* Added Olimex AVR-IO-M16 sources for ARV micro-controller.
* Removed setDirection() from GpioPin; embedded this functionality into existing setMode() method. Eliminating duplication.
* Removed old test programs from pi4j-core and moved wiringPi examples to pi4j-example project.
* Added support for I2C communication.
* Added blink() methods for GPIO pins
2012-09-23 :: 0.0.2-SNAPSHOT
* Refactored Gpio interface to permit methods using Pin argument to function without requiring a GpioPin to first be provisioned
* Added OSGi manifest
* Optimized GPIO interrupt thread handling to only be created if GpioPin listeners or triggers have been registered.
* Now disabling/stopping GPIO interrupt native thread monitoring if all GpioPin listeners or triggers are unregistered.
* Added additional convenience methods in GpioPin interface for evaluating state, direction, resistance, mode, etc.
* There were two Gpio classes; renamed one to GpioController to avoid confusion.
* Added OSGi service project to export Pi4J GPIO as an OSGi service.
2012-09-19 :: 0.0.1-SNAPSHOT
* Initial ALPHA release